This application claims priority to UK Application Serial No. 000799.0 filed Mar. 30, 2000, the disclosure of which is incorporated herein by reference.
The present invention relates to a modular conversion unit for converting punching machines from single-punch to multiple-punch.
Conventional punching machines for machining metal plates comprise a footing provided with a worktable and an overlying turret which supports the hammer acting on the punches.
In turn, the worktable is provided with an oppositely arranged die adapted to receive the tip of the punch whenever it is actuated in order to perforate a metal plate.
These punching machines suffer a lot of drawbacks, including the fact that it is not possible to have a plurality of punches simultaneously available without having to replace them, in each instance, in the corresponding support in order to perform mutually different kinds of machining.
A second drawback of conventional punching machines is the limited space available between the surface for supporting the plates to be machined and the lower face of the punch holder, which is usually of a few centimeters.
Consequently, maintenance, generally required by jamming of the plates and punches or of the plates and the underlying dies, due to the machining waste produced by using said machines, is performed with great difficulty.
Finally, removal of the dies, which must be performed every time the punch is replaced with another one, also entails objective difficulties caused by the complexity of the maneuvers to be performed in order to extract the die from its seat: in conventional punching machines it is in fact necessary to disassemble a significant part of the working platform in order to be able to free the seat of the dies.
The aim of the present invention is to solve the above-mentioned problems of the prior art by providing a modular conversion unit for converting punching machines from single-punch to multiple-punch which allows to have available a wide range of punches ready for use without having to perform replacements and also allows, by way of its configuration, easier access for operators in the interspace between the turret and the worktable and for rapid replacement of the lower dies.
This aim and other objects, which will become more apparent hereinafter, are achieved by a modular conversion unit for converting punching machines from single-punch to multiple-punch, characterized in that it comprises an upper main cylindrical magazine which is rotatably supported by a turret of the punching machine and is provided with a plurality of radial seats for accommodating corresponding upper secondary cylindrical magazines, each of which supports a preset number of punches and is surmounted by a corresponding hammer element which is fitted so as to rotate in a controlled way, a corresponding lower main cylindrical die-holder magazine which is accommodated so as to rotate synchronously with said upper cylindrical magazine and is vertically aligned coaxially thereto in a hollow seat which is formed in a working platform of the punching machine and is provided with a corresponding number of radial seats for accommodating lower secondary die-holders supported so as to be vertically aligned with said upper secondary magazines, each die-holder being provided with a plurality of dies whose number is equal to the number of said punches, a first motor means being provided for producing a controlled rotation of said upper main cylindrical magazine with respect to said turret, a second motor means being also provided which intervenes alternatively and is meant to actuate, with a controlled rotation, said hammer elements with respect to the corresponding secondary cylindrical magazines, a third motor means being provided for the controlled rotation of said lower main cylindrical magazine with respect to said seat synchronously with said upper main magazine.